Drill bit and stabilizer combination

ABSTRACT

A closely coupled bore hole drill bit and stabilizer combination includes a body structure adapted to be coupled to a rotary drill string or downhole motor, the body structure having cutting elements on its lower portion for drilling the bore hole, the upper portion of the body structure being surrounded by a separate stabilizer in juxtaposition to the upper end of the lower portion of the body structure, the stabilizer being removably coupled to the body structure, as through the agency of a clutch device, by a threaded coupling, or by welding, allowing readily uncoupling or disconnection of the stabilizer from a worn drill bit and its appropriate association with another operable drill bit.

United States Patent 1191 Flarity et a1,

1 1 July 23,1974

1 DRILL BIT AND STABILIZER COMBINATION Inventors: Frank ODell Flarity,SaltLake City, Utah; Waymon Rhea Eustace, Midland, Tex.

Assignee: Christensen Diamond Products Company, Salt Lake City, Utah 22Filed: Feb. 2, 1972' 211 AppL'No; 222,826

[52] US. Cl 175/394, 175/325, 175/329 [51] Int. Cl E211) 9/36, E21b17/10.

[58] Field of Search 175/394, 323, 325, 329,

[56] References Cited v UNITED STATES PATENTS Besson 175/403 XJenkins... 175 329 x Shields 175/412 X Mitchell 175/329 Lake 175/330Comstock 175/329 X 1571 A closely coupled bore hole drill bit andstabilizer 3,095,049 6/1963 DuBcrger l75/33OX 3,712,392 1/1973 DelaGorgendiere. 175/325 Rl1,597 4/1897 Davis 175/403 X PrimaryExaminer-Henry C. Sutherland Assistant ExaminerRichard E. FavreauAttorney, Agent, or Firm-Bernard Kriegel ABSTRACT combination includes abody structure adapted to be coupled to a rotary drill string ordownhole motor, the

bodyf structure having cutting elements on its lower portion fordrilling the bore hole, the upper portion of the body structure beingsurrounded by a separate stabilizer in juxtaposition to the upper end ofthe lower portion of the body structure, the stabilizer being re-imovably coupled to the body structure, as through the agency of a clutchdevice, by a threaded coupling, or by welding, allowing readilyuncoupling or disconnection of the stabilizer from a worn drill bit andits appropriate association with another operable drill bit.-

'18 Claims, 4 Drawing Figures Pennington 175/329 PATENTEDJUL23IS74 SHEET1 BF 2 1 Fm Jr a n. 0 w oo DO 9 a 0 0 0 0 a a 00 V 1 DRILL BIT ANDSTABILIZER COMBINATION The present invention relates to rotary bore holedrilling devices, and more particularly to combinations of drill bitsand stabilizers used in drilling bore holes, such as stabilizer anddiamond bitcombinations.

Rotary drill bit and stabilizer combinations are well known,thestabilizer having thepurpose, as its name implies, of retaining thebit in acoaxial or centered position in the bore hole being drilled.Heretofore, the stabilizer has been threadedly connected to the lowerend of a rotary drilling string, or a downhole motor, the

lower end of the stabilizer being threadedly connected to the upper endof the drill bit that drills the hole. With the prior stabilizer and bitcombinations, the bore hole being drilled by the bit may tend to deviatefrom the desired drilling direction; the bit may wobble, tending todrill a spiraled, oversize hole; it may form ledges in the hole; and-itmay cause excessive wear on and damage to the bit. cutting elements,contributing to a slower drilling rate and to a lesser bit life.

By virtue of the present invention,*a bit stabilizer combination isprovided that results in the drilling of a truer and straighter bore"hole. Wobbling of the bit, such as a diamond bit is eliminated,reducing the tendency of the bit to'drill spiraled, oversized holes.Darting of the bit around the bottom of the bore hole is alsoeliminated, preventing ledges from being formed in the hole. Since thebit is caused to drill a truer size'hole, its penetration rate into theformation is increased, excess wear of and damage to the diamonds orother cutting elements is avoided, contributing to a longer life of thebit. 1

The drill bit and stabilizer are closely coupled to each other, runningtruer and providing a longer life to the bearings of a downhole motorthat might be used in rotating the bit and stabilizer combination, aswell as reducing power losses inherent in the greater overall length ofprior drill bit and stabilizer combinations.

In apparatus embodying the present invention, the stabilizer portion isrotatably driven directly by the .body structureof the bit, thestabilizer being relatively easily disconnected from a worn bit andreadily reconnectable to the body structure of anew bit, therebyenabling the stabilizer to outlast several drill bits, providing readyreplacement in the field, if desired, of bits or stabilizers in thebit-stabilizer combination. With stabilizer-diamond bit combinations,the stabilizer, in effect, forms an upward continuation of the bit, thestabilizer pads or landsbeing positively-alignable with the pads orlands on the reamer portion of the bit, the waterways or junk slotsbetween the stabilizer pads also being aligned with the correspondingwaterways or junks slots in the bit reamerportion, the stabilizer padsand junk slots forming upward continuations of the bit reamerpads andjunk slots, respectively, there being no significant gaps between thestabilizerand bit reamer portion. x

This invention possesses many other advantages,'and has other purposeswhich may be made more clearly apparent-from a consideration of severalforms in which it may be embodied. Such forms are shown in the ples ofthe invention; but it is to be understoodthat 2 such detaileddescription is not to be taken in a limiting sense.

Referring to the drawings:

FIG. 1 is a side elevational view of a rotary drill bit.

As disclosed in the drawings, a combined drill bit and stabilizerincludes a drill bit A foroperation upon the bottom of a bore hole,drilling fluid flushing the cuttings from the bottom upwardly around thedrill bit and a string of drill pipe. (not shown) to which it is securedto the top of the hole. It also includes a stabilizer B for maintainingthe bit coaxial of the bore hole. The combined drill bit and stabilizerincludes a body or shank structure 10 comprising an upper section 11having an upper threaded pin 12 for threadedly attaching the combinationto the string of drill pipe. The upper section is attached by;a straightthreaded connection 13 and weld 14 to a lower section 15. Circulatingfluid pumped down through the drill pipe flows into a central or mainpassage 16 of the body structure of the tool and then flows through aplurality of circumferentially spaced longitudinally extending grooves17 toward the bottom of the hole. The lower end of each fluiddistribution groove communicates with one or a plurality of radialwaterways 18 extending toward the outer gage portion 19 of the bit, thefluid flowing through such waterways and also across the cutting surfaceor face of the bit.

. The body of the bit has diamonds or similar cutting elements 20secured in its formation contacting face within a matrix 21, of asuitable type, forming a portion of thebit body 10 and appropriatelyfused to its lower body section 15. The central portion 22 of the bitillustrated is generally conical in shape with the side of the conetapering in an upward and inward direction. The generally conicalportion of the bit merges into'a lower bottom contacting portion 23,which, in turn, merges into an upwardly diverging conical face 24terminating at the generally cylindrical reamer face 25 of the bit. Thedrilling portion of the bit A is divided into a plurality of diamond setsections, lands or pads 26, 26a which extend outwardly from the regionof the distribution grooves 17, and which are defined by the waterways18 extending from each groove toward the gage portion 19 of the bit.Thus, the waterways extend from the outlets of the distribution grooves17 generally radially along the inner conical face portion 22,-lowermost face portion 23, and outer conical face portion 24,

merging into vertical waterways or grooves 27, 27b in' the reamerportion 19 of the bit body section 15, the upper portions of some of thevertical waterways running transversely across the gage portions 19 andopening into circumferentially spaced vertical junk slots 27b in thereamer portion that-extend upwardly through its upper end.

The inner conical portion 22 of the bit face has diamonds 20.set in itsmatrix 21 for operation upon the central portion of the hole. Similarly,diamonds are set in a predetermined pattern in the faces of all of thelands, the diamonds 20 terminating at the lowermost 3 end 30 of theouter gage or vertical reamer portion 19. Such reamer portion may havediamonds or other suitable cutting elements 20 a in its matrix 21.

in the form of the invention illustrated in FIGS. 1 to 3', thestabilizer B is mounted on the bit body 10. This stabilizer is in theform of a sleeve unit 31 that can be slippeddownwardly over the body orshank l0, with its lower end 32 bearing against the upper-end 33 of theouter matrix 21 of the drill bit. The inside diameter of the stabilizersleeve '31 conforms closely to the outside diameterof the upper bodysection 11 and of the upper portion of the lower body section 15,leakage of fluid between the sleeve and body sections being prevented byseveral elastomer seal rings 34, such as O-rings, disposed incircumferential grooves 35 in the body sections and bearing against theinner wall 31a of the sleeve. The sleeve has circumferentiallyspacedvertical lands or pads 36 formed thereon which are defined byintervening vertical waterways37 and junk slots'37a.

The'stabilizer lands, waterways and junk slots conform in spacing andwidth with the waterways 27, junk slots 27b and lands 26a in the reameror gage portion 19 of the lower drill bit and form upward continuationsthereof, the stabilizer junk slots 37a and waterways 37 opening throughthe upper end of the stabilizer sleeve, with the lands 36 terminating ata tapered guide shoulder 38 inclined in a downward and outwarddirection.

Appropriate orienting of the stabilizer sleeve 31 with the lower drillbit A, to align the stabilizer pads, water- 1 ways and junk slots withthe reader pads, waterways and junk slots, is secured through a clutchor coupling device 40. Thus, the outer part of the gage portion 19 hasaxial vertical grooves-41 therein in the vertical landsl-9 that receivedownwardly directed clutch dogs or teeth 42 integral with the stabilizerlands 36, the

tion 32 engages the upwardly facing shoulder 33on the bit matrix 21, andwith the stabilizer dogs 42 interfitting fully with the dogs 44 of thereamer portion 19 of the drill bit. The nut 51 is prevented fromloosening from its tight position on the body of the bit by a lock nut53 threaded onthe threaded bit body portion 52 and tightened firmlyagainst the jam nut 51.

In operation of the drill bit and stabilizer combination, the upperthreaded pin 12 is secured to the lower end of the drill pipe string ordownhole motor and is lowered in the'bore hole being drilled to itsbottom. Suitable'drilling weight is imposed on the drilling string andbody of the tool while the tool isrotated atthe desired speed anddrilling mudis circulated down through the drill pipe and through thecentral or'main fluid .passage 16 of the bit. The'stabilizer pads36 havethe same bearing dianieter 'as the vertical reamer pads 26a of the drillbit 'A and serves to center the drill bit in the hole,

the cuttings being flushed by the drilling fluid toward the outerportion of the bit and through the waterways 27 and junk slots 27b ofthe bit, continuing upwardly through the waterways 37 and junk slots 37aof the stabilizer B, the drilling fluid also flowing across the severaldrilling pads 26a and the stabilizer pads 36 to-cool them and also toclean them of cuttings.-

The close coupled relationship between the stabilizer sleeve 31 andthedrill bit portion A of the combination results in the drilling of a trueand straight holerwobblingof theadrill bit portion being eliminated,which reduces the tendency of the bit to drill a spiraled oversize hole,as well as preventing ledges from 'beingformed in the hole. Since thebit is drilling the desired size of hole,

, its penetration rate is increased, while the life of the bit width ofthe dogs 42 and grooves 41 closely conforming and providing a rotatabledriving connection between the bit'A and the stabilizer sleeve 31. Ineffect, the stabilizer teeth or dogs 42 are formed by circumferentiallyspaced lower grooves 43 in the stabilizer sleeve which receive upwardlyprojecting dogs or teeth 44 of .the

is extended by avoiding excessive damage to its cutting elements ordiamonds. I A

The stabilizer portion of the combination will outlast three to fivediamond bits, enabling it to be used with a plurality of successivedrill bits. Thus, after the apparatus has been withdrawn from the borehole the stabilizer sleeve 31 is easily removed by unscrewing the locknut 53 and jam nut 51 and slipping the stabilizer sleeve reamer portion19 of the bit, such reamer dogs defining the grooves 41 that receive thestabilizer axial dogs 42. It is to be noted that the widths of the dogsor teeth 42, 44 closely conform to the widths of the grooves 41, 43 sothat a torque'with substantially no play can be transmitted from thereamer bit ,dogs 44 to the stabilizer 'dogs 42. Not only do theinterengaging clutch teeth or dogs 44, 42 serve to transmit rotationfrom the bit portion A of the tool to the. stabilizer sleeve 31, but itserves to properly align the stabilizer pads 36, waterways 37 and junkslots 37a with the reamer pads 26a,-

waterways 27, and junk slots 27b, respectively of the bit. Preferably,the reamer pads and stabilizer pads and the waterwaysand junk slotstherebetween are inclined so that 360 wall coverage can be obtained bythe stabilizer and reamer portions of the bit combination. Thestabilizer pads 36 have suitable hard material embedded in their outermatrix portion, which may be diamonds, sintered carbide inserts, orcombinations.

thereof.

The stabilizer sleeve 31 is rigidly secured to the bit body and alsofirmlycoupled to the drill bit A by a jam nut 51 threaded downwardly onan externally threaded portion 52 of the bit body section 11, this nutbeing tightened untilthe inner or lower stabilizer sleeve porupwardlyoff the drill bit body section 11, enabling it to be slipped overanother bit body and placed in clutched or coupled relation with anotherdrill bit portion of the bit and stabilizer combination, thesleeve'being secured in place by the jam and lock nuts 51, 53.

In the form of the invention disclosed in FIG. 4, the stabilizer sleeve31a is not clutched to the drill bit portion. Instead, the sleeve has anupper threaded box that is mounted on the external thread 71 of anintermediate body section 72, the lower end 73 of which is threaded tothe lower body section 15a, also being attached thereto by a weld 14.The stabilizer sleeve 31a is threaded downwardly until its lower end 32aengages an upwardly facing shoulder 33 on the lower body section 15a, atwhich time the stabilizer pads 36, waterways 37 and junk slots 37a willbe alignedwith the companion pads, waterways and junk slots of thereamer portion 19 of the drill bit. When so aligned, a

downwardly facing inner shoulder 75' on the stabilizer diate bodysection 72.

The stabilizer sleeve 31a is firmly secured to the intermediate section72 by threading an upper section 11a to the upper portion of theintermediate section 72 and then welding the upper section 11a,intermediate section 72 and sleeve 31a together by a circumferentialweld 77, which is then turned off so that its periphery conforms to theperipheries of the upper section 11a and stabilizer sleeve 31a. Theupper body section has a threaded pin 12 thereon for securing the bitstructure to the lower end of a drilling string or drilling motor, bymeans of which the entire bit and stabilizer assembly is rotated.

ln drilling the bore hole with the stabilizer and drill bit combinationillustrated in FIG. 4, the torque is transmitted from the drill stringor motor through the upper body section, 11a and intermediate bodysection 72 to the lower drill bit A. ltis also 'transmittedfrom theupper body section through the intermediate body section and weld 77tothe stabilizer sleeve 31a, such that the stabilizer sleeve and drillbit rotate as a functionally integral unit. i

The mode of operation and advantages of the assembly illustrated in FIG4 are essentially the same as in the other form of the invention,including the removability of the stabilizer sleeve 31a from the bodystructureand lower drill bit. Thus, the weld 77 can be cut away and theupper body section 11a unthreaded from the intermediate body section 72,which then enables the stabilizer sleeve 31ato be unthreaded'from theintermediate' body section 72, for use in combination with another andnew drill bit.

- We claim;

1. In a rotary drill bit and stabilizer apparatus for drilling a borehole in a formation: a body structure having an upper connector adaptedto secure said structure to a drilling string; said body structurehaving a lower cutting portion for drilling the bore hole to apredetermined diameter and an outer gage portion of extended lengthintegral with said lower cutting portion and having an effectivediameter conforming to said predetermined bore hole diameter; aseparateelongate stabilizer movable over said connector and along said bodystructure toward and into engagement with said outer gage portion; andmeans for securing said stabilizer to said body structure forsimultaneous rotation with said lower cutting portion, said stabilizerhaving circumferentially spaced, externally arcuate elongate verticalpads providing a large bearing area with respect to the wall surface ofthe bore hole, said pads having an effective diameter conforming to thediameter of said hole and outer gage portion, the lower end of saidstabilizer being contiguous the upper end of said gage portion, saidstabilizer constituting an upward continuation of said gage portion.

2. ln apparatus as defined in claim 1; said stabilizer comprising anelongate sleeve having an effective outside diameterconforming to thepredetermined bore hole diameter; said securing means securing saidsleeve to said body structure for rotation by said body structurejointly with said lower cutting portion.

3. In apparatus as defined in claim 1; said lower cutting portionincluding a fluid passage and spaced waterways in the end face of saidcutting portion communicating with said passage andproviding lands insaid end face therebetween; cuttingelements on said lands; said gageportion having spaced vertical waterways in its periphery communicatingwith said otherwaterways and providing spaced vertical landstherebetween; said stabilizer having spaced vertical elongate waterwaysin its periphery aligned with and communicating with said verticalwaterways of said gage portion, said stabilizer waterways defining saidspaced vertical elongate pads therebetween forming upward continuationsof the vertical gage portion lands; the lower ends of said stabilizerwaterways and stabilizer pads being contiguous the upper ends of saidgage portion vertical waterways and vertical lands, respectively.

4. ln apparatus as defined in claim 1; said stabilizer comprising anelongate sleeve having an effective outside diameter conforming to thepredetermined bore hole diameter; said securing means securing saidsleeve to said body structure for rotation by said body structurejointly with-said lower cutting portion; said lower cuttingportionincluding a fluid passage and spaced waterways in the end face ofsaid cutting portion communicating with said passage and providing landsin said end face therebetween; cutting elements on said lands; said gageportion having spaced vertical waterways in itsperiphery communicatingwith said other waterways and providing spaced vertical landstherebetween; said stabilizer sleeve having spaced vertically elongatewaterways in its periphery aligned with and communicating with said"vertical waterways of said gage portion, said stabilizer sleevewaterways said spaced vertical elongate pads therebetween forming upwardcontinuations of thevertical gage portion lands; the lower ends of saidstabilizer sleeve waterways and stabilizer sleeve pads being contiguousthe upper ends of said gage portion vertical waterways and verticallands, respectively. y

5. ln rotary drill bit and stabilizer apparatus for drilling a bore holein a formation: a body structure having an upper connector adapted tosecure said structure to a drilling string; said body structure having alower cutting portion for drilling the bore hole to a predetermineddiameter and anouter gate portion of extended length integral with saidlower cutting portion and having an effective diameter conforming tosaid predetermined bore hole diameter; a separate elongate stabilizersleeve movable over said connector and along the exterior of said bodystructure above said outer gage portion toward and into engagement withsaid outer gate portion, said sleeve having circumferentially spaced,externally arcuate elongate vertical pads providing a large bearing areawith respect to the wall surface of the bore hole, said pads having aneffective diameter conforming to the diameter of said hole and outergage portion, the lower end of said sleeve being contiguous the upperend of said gage portion, said sleeve constituting an upwardcontinuation of said gage portion; and clutching means securing saidsleeve to said body structure, whereby said cutting portion and sleeverotate together. f

6.- In apparatus as defined in claim 5; said clutching means comprisingintermeshing axially extending dogs on the lower portion of said sleeveand upper portion of said gage portion.

7. ln apparatus as defined in claim 5; and means on said body structureengaging said sleeve for holding said sleeve downwardly andsaidclutching means engaged. y

8. In apparatus as defined in claim 5; said clutching means comprisingintermeshing axially extending dogs on the lower portion of said sleeveand upper portion of said gage portion; and means on said body structureengaging said sleeve for holding said sleeve downwardly and said dogsintermeshed.

9 ln apparatus as defined in claim 5; and means on said body structureengaging said sleeve for holding I said sleeve downwardly and saidclutching means engaged; and means threaded on said body structure abovesaid sleeve'and engaging the upper end of said sleeve for holding saidsleeve downwardly and said dogs 'intermeshed.

10. In apparatus as defined in claim said lower cutting portionincluding a fluid passage and spaced waterways in the end face of saidcutting portion communicatingwith said passage and providing lands insaid end face therebetween; cutting elementson said lands; said withsaid verticalwaterways of said gage portion, said stabilizersleeve'waterways defining said spaced vertical elongate padstherebetween forming upward continuationsof the vertical gageportion'lands; the lower ends of said stabilizer sleeve waterways andstabilizer sleeve pads being contiguous the upper ends-of said gageportion vertical waterways and verticallands,'respectively. a a I 11. Inapparatus as defined in claim 5; said lower cutting portion including afluid passage and spaced waterways in the endface of saidcutting portioncommunicating with said passage and providing lands in= said end facetherebetween; cutting elements on said'lands; said gageportion havingspaced vertical waterways in its periphery'communicating with said otherwaterways and providing spaced vertical landstherebetween; saidstabilizer sleeve having spaced vertical elongate waterways in itsperiphery aligned with and communicating with said vertical waterways ofsaid gage portion, said stabilizer sleeve waterwaysdefining said spacedvertical elongate. pads the'rebetween forming upward continuations ofthe vertical gage portion lands; the lower ends of said stabilizersleeve waterways and stabilizer sleeve pads being contiguous the upperends of said gage portion vertical waterways and vertical lands, re-

' spectively; said clutching means comprising intermesh- 'ing axiallyextending dogs on the lower portion of said sleeve and upper portion ofsaid gage portion; and

means on said body'structure engaging said sleeve for holding said;sleeve downwardly and said dogs intern 12. In rotary drillbit andstabilizer apparatus for drilling a bore hole in a formation: a bodystructure adapted to be connected to a drilling string; said body Istructure having a lower cutting portion for drilling the bore hole to apredetermined diameter, said lower'cutting portion including an outergage portion of an effective diameter conforming to said predeterminedbore hole diameter; a separate stabilizersleeve encompassingsaid bodystructure'above said outer gage portion, said sleeve having an effectivediameter conforming to the diameter of said hole and outer gageportion,the lower end of said sleeve being contiguous 'the upper end of saidgage portion, said sleeve constituting an upward continua'tion'of saidgage portion; and clutching means securing said sleeve to said bodystructure,

whereby said cutting portion and sleeve rotate together; said lowercutting portion including a fluid pas sage and spaced waterways in theend face of said cutting portion communicating with said passage andproviding lands in said end face therebetween; cutting elements on saidlands; said .gage portion having spaced 8 vertical waterways in itsperiphery communicating with said other waterways and providing spacedvertical lands .therebetween; said stabilizer sleeve having spacedvertical elongate waterways in its periphery aligned with andcommunicating with said vertical waterways of said gage portion, saidstabilizer sleeve waterways defining spaced vertical elongate landstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer sleeve waterways andstabilizer'sleeve lands being contiguous the upper ends of said gageportion vertical waterways and-vertical lands, respectively; saidclutching means comprising intermeshing axially extending dogs onthelower portion of said sleeveand upper portion of said gage portion;and means threaded on said body structure and engaging the upper end ofsaid sleeve for holding said sleeve downwardly and said dogsintermeshed.

' 13. In rotary drill bit and-stabilizer apparatus for drilling a borehole in a formation: abody structure having an upper connector adaptedto secure said'str ucture to a drilling string; said body structurehaving a lower cutting portion for drilling the'bore hole to apredetermined diameter and an outer gage portion of extended lengthintegral with said lower cutting portion and having an effectivediameter conformingto said predetermined bore hole diameter; a separatestabilizer-sleeve movable over said connector and along the exterior ofsaid body structure above said. outer gage port-ion toward andinto'engagement' with said outer gage portion, said sleeve havingcircumferentially spaced, externally arcuat eelongate vertical padsproviding a large bearing area with respect to the'wall surface of thebore hole, said pads having an effective diameter conforming to thediameter of said hole and outer gage portion,

the'lower end of said sleeve being contiguous the upper curing the upperportion of said sleeve to said body structure,.whereby said cuttingportion and sleeve rotate together Y 14. In apparatus as defined. inclaim 13; said securing means including athreaded connection betweensaid body'structureand upper portion of said stabilizer sleeve. i M

15. In apparatus as defined in claim 13; said lower cutting portionincluding a fluid passage and, spaced waterways in the end face of saidcutting portion communicating with said passage andproviding lands insaid end face therebetween; cutting elements on said lands; said gageportion havingspaced verticalwaterways in its periphery communicatingwith said other waterways and providing spaced vertical-landstherebetween; said stabilizer sleeve having spaced vertical elongatewaterways in its peripheryaligned with and communicating with saidvertical waterways of said gage portion, said stabilizer sleevewaterways defining said spaced vertical elongate padstherebetweenforming upward continuations of the vertical gage portion lands; thelower ends of said stabilizer sleeve waterways and stabilizer sleevepads being contiguous the upper said end face therebetween; cuttingelements on said lands; said gage portion having spaced verticalwaterways in its periphery communicating with said other waterways andproviding spaced vertical lands therebetween; said stabilizer sleevehaving spaced vertical elongate waterways in its periphery aligned withand communicating with said vertical waterways of said gage portion,saidstabilizer sleeve waterways defining said spaced vertical elongatepads therebetween forming upward continuations of the vertical gageportion lands; the lower ends of saidstabilizer sleeve waterways andstabilizer sleeve pads being contiguous the upper ends of said gageportion vertical waterways and vertical lands, respectively; saidsecuring means including a threaded connection between said bodystructure and upper portion of said stabilizer sleeve.

17. In rotary drill bit and stabilizer apparatus for drilling a borehole ina formation: a body structure having an upper connector adaptedto secure said structure to a drilling string; said body structurehaving a lower cutting portion for drilling the bore hole to apredetermined diameter, said lower cutting portion including an outergage portion of an effective diameter conforming to said predeterminedbore hole diameter; a separate stabilizer sleeve movable over saidconnector and along the exterior of said body structure above said outergage portion toward and into engagement with said outer gage portion,said sleeve having an effective diameter conforming to the diameter ofsaid hole and outer gage portion, the lower end of said sleeve beingcontiguous the upper end of said gage portion, said sleeve constitutingan upward continuation of said gage portion; and means securing theupper portion of said ling a bore hole in formation: a body structurehaving an upper connector adapted to secure said structure to a drillingstring; said body structure having a lower cutting portion for drillingthe bore hole to a predetermined diameter, said lower cutting portionincluding an outer gage portion of an effective diameter conforming tosaid predetermined bore hole diameter; a separate stabilizer sleevemovable over said connector and along the exterior of said bodystructure above said outer gage portion toward, and into engagement withsaid outer gage portion, said sleeve having an effective diameterconforming to the diameter of said hole and outer gage portion, thelower end of said sleeve being contiguous the upper end of said gageportion, said sleeve constituting an upward continuation of said gageportion; and means securing the upper portion of said sleeve to saidbody structure, whereby said cutting portion and sleeve rotate together;said lower cutting portion including a fluid passage and spacedwaterways in the end face of said cutting portion communicating withsaid passage and providing lands in said end face therebetween; cuttingelements on said lands; said gage portion having spaced verticalwaterways in its periphery communicating with said other waterways andproviding spaced vertical lands therebetween; said stabilizer sleeverhaving spaced vertical elongate waterways in its periphery aligned withand communicating with said vertical waterways of said gage portion,said stabilizer sleeve waterways defining spaced vertical elongate landstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer sleeve waterways and stabilizersleeve lands being contiguous the upper ends of said gage portionvertical waterways and vertical lands, respectively; said securing meansincluding a threadedconnection between said body structure and upperportion of said stabilizer sleeve; said securing means further includinga weld integrating said upper portion of said sleeve to said bodystructure. I

cm'm 1mm 01* wmmcuam P NO. bated my 74 v 1 v V 1nventor(s) FRANK O'DELLFLARITY and W AYMON RHEA EUSICE It is crtificd that error abp'cars inthe above-identified patent: 3nd that said Latte-rs Patent are hezjebycorrected as s ho\-m below:

Y v Y '9 Column -6, line aftei; iiwatin" n r df fining I Signed a nd-s;;1d 'm-1s 19 day' of "Nove r'nber. 1974;.

(SEAL) l Attest I i McCGY M. GIBSON-JR. T c. MARSH'A-LL'DANN". v

Attest ing Officer a Comissioner 9f Patents

1. In a rotary drill bit and stabilizer apparatus for drilling a borehole in a formation: a body structure having an upper connector adaptedto secure said structure to a drilling string; said body structurehaving a lower cutting portion for drilling the bore hole to apredetermined diameter and an outer gage portion of extended lengthintegral with said lower cutting portion and having an effectivediameter conforming to said predetermined bore hole diameter; a separateelongate stabilizer movable over said connector and along said bodystructure toward and into engagement with said outer gage portion; andmeans for securing said stabilizer to said body structure forsimultaneous rotation with said lower cutting portion, said stabilizerhaving circumferentially spaced, externally arcuate elongate verticalpads providing a large bearing area with respect to the wall surface ofthe bore hole, said pads having an effective diameter conforming to thediameter of said hole and outer gage portion, the lower end of saidstabilizer being contiguous the upper end of said gage portion, saidstabilizer constituting an upward continuation of said gage portion. 2.In apparatus as defined in claim 1; said stabilizer comprising anelongate sleeve having an effective outside diameter conforming to thepredetermined bore hole diameter; said securing means securing saidsleeve to said body structure for rotation by said body structurejointly with said lower cutting portion.
 3. In apparatus as defined inclaim 1; said lower cutting portion including a fluid passage and spacedwaterways in the end face of said cutting portion communicating withsaid passage and providing lands in said end face therebetween; cuttingelements on said lands; said gage portion having spaced verticalwaterways in its periphery communicating with said other waterways andproviding spaced vertical lands therebetween; said stabilizer havingspaced vertical elongate waterways in its periphery aligned with andcommunicating with said vertical waterways of said gage portion, saidstabilizer waterways defining said spaced vertical elongate padstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer waterways and stabilizer padsbeing contiguous the upper ends of said gage portion vertical waterwaysand vertical lands, respectively.
 4. In apparatus as defined in claim 1;said stabilizer comprising an elongate sleeve having an effectiveoutside diameter conforming to the predetermined bore hole diameter;said securing means securing said sleeve to said body structure forrotation by said body structure jointly with said lower cutting portion;said lower cutting portion including a fluid passage and spacedwaterways in the end face of said cutting portion communicating withsaid passage and providing lands in said end face therebetween; cuttingelements on said lands; said gage portion having spaced verticalwaterways in its periphery communicating with said other waterways andproviding spaced vertical lands therebetween; said stabilizer sleevehaving spaced vertically elongate waterways in its periphery alignedwith and communicating with said vertical waterways of said gageportion, said stabilizer sleeve waterways said spaced vertical elongatepads therebetween forming upward continuations of the vertical gageportion lands; the lower ends of said stabilizer sleeve waterways andstabilizer sleeve pads being contiguous the upper ends of said gageportion vertical waterways and vertical lands, respectively.
 5. Inrotary drill bit and stabilizer apparatus for drilling a bore hole in aformation: a body structure having an upper connector adapted to securesaid structure to a drilling string; said body structure having a lowercutting portion for drilling the bore hole to a predetermined diameterand an outer gate portion of extended length integral with said lowercutting portion and having an effective diameter conforming to saidpredetermined bore hole diameter; a separate elongate stabilizer sleevemovable over said connector and along the exterior of said bodystructure above said outer gage portion toward and into engagement withsaid outer gate portion, said sleeve having circumferentially spaced,externally arcuate elongate vertical pads providing a large bearing areawith respect to the wall surface of the bore hole, said pads having aneffective diameter conforming to the diameter of said hole and outergage portion, the lower end of said sleeve being contiguous the upperend of said gage portion, said sleeve constituting an upwardcontinuation of said gage portion; and clutching means securing saidsleeve to said body structure, whereby said cutting portion and sleeverotate together.
 6. In apparatus as defined in claim 5; said clutchingmeans comprising intermeshing axially extending dogs on the lowerportion of said sleeve and upper portion of said gage portion.
 7. Inapparatus as defined in claim 5; and means on said body structureengaging said sleeve for holding said sleeve downwardly and saidclutching means engaged.
 8. In apparatus as defined in claim 5; saidclutching means comprising intermeshing axially extending dogs on thelower portion of said sleeve and upper portion of said gage portion; andmeans on said body structure engaging said sleeve for holding saidsleeve downwardly and said dogs intermeshed.
 9. In apparatus as definedin claim 5; and means on said body structure engaging said sleeve forholding said sleeve downwardly and said clutching means engaged; andmeans threaded on said body structure above said sleeve and engaging theupper end of said sleeve for holding said sleeve downwardly and saiddogs intermeshed.
 10. In apparatus as defined in claim 5; said lowercutting portion including a fluid passage and spaced waterways in theend face of said cutting portion communicating with said passage andproviding lands in said end face therebetween; cutting elements on saidlands; said gage portion having spaced vertical waterways in itsperiphery communicating with said other waterways and providing spacedvertical lands therebetween; said stabilizer sleeve having spacedvertical elongate waterways in its periphery aligned with andcommunicating with said vertical waterways of said gage portion, saidstabilizer sleeve waterways defining said spaced vertical elongate padstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer sleeve waterways and stabilizersleeve pads being contiguous the upper ends of said gage portionvertical waterways and vertical lands, respectively.
 11. In apparatus asdefined in claim 5; said lower cutting portion including a fluid passageand spaced waterways in the end face of said cutting portioncommunicating with said passage and providing lanDs in said end facetherebetween; cutting elements on said lands; said gage portion havingspaced vertical waterways in its periphery communicating with said otherwaterways and providing spaced vertical lands therebetween; saidstabilizer sleeve having spaced vertical elongate waterways in itsperiphery aligned with and communicating with said vertical waterways ofsaid gage portion, said stabilizer sleeve waterways defining said spacedvertical elongate pads therebetween forming upward continuations of thevertical gage portion lands; the lower ends of said stabilizer sleevewaterways and stabilizer sleeve pads being contiguous the upper ends ofsaid gage portion vertical waterways and vertical lands, respectively;said clutching means comprising intermeshing axially extending dogs onthe lower portion of said sleeve and upper portion of said gage portion;and means on said body structure engaging said sleeve for holding saidsleeve downwardly and said dogs intermeshed.
 12. In rotary drill bit andstabilizer apparatus for drilling a bore hole in a formation: a bodystructure adapted to be connected to a drilling string; said bodystructure having a lower cutting portion for drilling the bore hole to apredetermined diameter, said lower cutting portion including an outergage portion of an effective diameter conforming to said predeterminedbore hole diameter; a separate stabilizer sleeve encompassing said bodystructure above said outer gage portion, said sleeve having an effectivediameter conforming to the diameter of said hole and outer gage portion,the lower end of said sleeve being contiguous the upper end of said gageportion, said sleeve constituting an upward continuation of said gageportion; and clutching means securing said sleeve to said bodystructure, whereby said cutting portion and sleeve rotate together; saidlower cutting portion including a fluid passage and spaced waterways inthe end face of said cutting portion communicating with said passage andproviding lands in said end face therebetween; cutting elements on saidlands; said gage portion having spaced vertical waterways in itsperiphery communicating with said other waterways and providing spacedvertical lands therebetween; said stabilizer sleeve having spacedvertical elongate waterways in its periphery aligned with andcommunicating with said vertical waterways of said gage portion, saidstabilizer sleeve waterways defining spaced vertical elongate landstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer sleeve waterways and stabilizersleeve lands being contiguous the upper ends of said gage portionvertical waterways and vertical lands, respectively; said clutchingmeans comprising intermeshing axially extending dogs on the lowerportion of said sleeve and upper portion of said gage portion; and meansthreaded on said body structure and engaging the upper end of saidsleeve for holding said sleeve downwardly and said dogs intermeshed. 13.In rotary drill bit and stabilizer apparatus for drilling a bore hole ina formation: a body structure having an upper connector adapted tosecure said structure to a drilling string; said body structure having alower cutting portion for drilling the bore hole to a predetermineddiameter and an outer gage portion of extended length integral with saidlower cutting portion and having an effective diameter conforming tosaid predetermined bore hole diameter; a separate stabilizer sleevemovable over said connector and along the exterior of said bodystructure above said outer gage portion toward and into engagement withsaid outer gage portion, said sleeve having circumferentially spaced,externally arcuate elongate vertical pads providing a large bearing areawith respect to the wall surface of the bore hole, said pads having aneffective diameter conforming to the diameter of said hole and outergage portion, the lower end of said sleeve being contiguous the upperend of said gage portion, Said sleeve constituting an upwardcontinuation of said gage portion; and means securing the upper portionof said sleeve to said body structure, whereby said cutting portion andsleeve rotate together.
 14. In apparatus as defined in claim 13; saidsecuring means including a threaded connection between said bodystructure and upper portion of said stabilizer sleeve.
 15. In apparatusas defined in claim 13; said lower cutting portion including a fluidpassage and spaced waterways in the end face of said cutting portioncommunicating with said passage and providing lands in said end facetherebetween; cutting elements on said lands; said gage portion havingspaced vertical waterways in its periphery communicating with said otherwaterways and providing spaced vertical lands therebetween; saidstabilizer sleeve having spaced vertical elongate waterways in itsperiphery aligned with and communicating with said vertical waterways ofsaid gage portion, said stabilizer sleeve waterways defining said spacedvertical elongate pads therebetween forming upward continuations of thevertical gage portion lands; the lower ends of said stabilizer sleevewaterways and stabilizer sleeve pads being contiguous the upper ends ofsaid gage portion vertical waterways and vertical lands, respectively.16. In apparatus as defined in claim 13; said lower cutting portionincluding a fluid passage and spaced waterways in the end face of saidcutting portion communicating with said passage and providing lands insaid end face therebetween; cutting elements on said lands; said gageportion having spaced vertical waterways in its periphery communicatingwith said other waterways and providing spaced vertical landstherebetween; said stabilizer sleeve having spaced vertical elongatewaterways in its periphery aligned with and communicating with saidvertical waterways of said gage portion, said stabilizer sleevewaterways defining said spaced vertical elongate pads therebetweenforming upward continuations of the vertical gage portion lands; thelower ends of said stabilizer sleeve waterways and stabilizer sleevepads being contiguous the upper ends of said gage portion verticalwaterways and vertical lands, respectively; said securing meansincluding a threaded connection between said body structure and upperportion of said stabilizer sleeve.
 17. In rotary drill bit andstabilizer apparatus for drilling a bore hole in a formation: a bodystructure having an upper connector adapted to secure said structure toa drilling string; said body structure having a lower cutting portionfor drilling the bore hole to a predetermined diameter, said lowercutting portion including an outer gage portion of an effective diameterconforming to said predetermined bore hole diameter; a separatestabilizer sleeve movable over said connector and along the exterior ofsaid body structure above said outer gage portion toward and intoengagement with said outer gage portion, said sleeve having an effectivediameter conforming to the diameter of said hole and outer gage portion,the lower end of said sleeve being contiguous the upper end of said gageportion, said sleeve constituting an upward continuation of said gageportion; and means securing the upper portion of said sleeve to saidbody structure, whereby said cutting portion and sleeve rotate together;said securing means including a threaded connection between said bodystructure and upper portion of said stabilizer sleeve; said securingmeans further including a weld integrating said upper portion of saidsleeve to said body structure.
 18. In rotary drill bit and stabilizerapparatus for drilling a bore hole in formation: a body structure havingan upper connector adapted to secure said structure to a drillingstring; said body structure having a lower cutting portion for drillingthe bore hole to a predetermined diameter, said lower cutting portionincluding an outer gage portion of an effective diameter conforming tosaid predetermined boRe hole diameter; a separate stabilizer sleevemovable over said connector and along the exterior of said bodystructure above said outer gage portion toward and into engagement withsaid outer gage portion, said sleeve having an effective diameterconforming to the diameter of said hole and outer gage portion, thelower end of said sleeve being contiguous the upper end of said gageportion, said sleeve constituting an upward continuation of said gageportion; and means securing the upper portion of said sleeve to saidbody structure, whereby said cutting portion and sleeve rotate together;said lower cutting portion including a fluid passage and spacedwaterways in the end face of said cutting portion communicating withsaid passage and providing lands in said end face therebetween; cuttingelements on said lands; said gage portion having spaced verticalwaterways in its periphery communicating with said other waterways andproviding spaced vertical lands therebetween; said stabilizer sleeverhaving spaced vertical elongate waterways in its periphery aligned withand communicating with said vertical waterways of said gage portion,said stabilizer sleeve waterways defining spaced vertical elongate landstherebetween forming upward continuations of the vertical gage portionlands; the lower ends of said stabilizer sleeve waterways and stabilizersleeve lands being contiguous the upper ends of said gage portionvertical waterways and vertical lands, respectively; said securing meansincluding a threaded connection between said body structure and upperportion of said stabilizer sleeve; said securing means further includinga weld integrating said upper portion of said sleeve to said bodystructure.